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Related papers: Automated computation of scattering amplitudes

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We report on the advances in the calculation of the two-loop scattering amplitudes for five-particle processes with one off-shell leg. Focusing on the production of a Higgs boson in association with a bottom quark pair, we outline how the…

High Energy Physics - Phenomenology · Physics 2023-03-01 Jakub Kryś

We discuss algebraic/numeric methods to compute one-loop corrections for multiparticle/jet production cross sections. By using efficient reduction algorithms a compact expression for the ggg\gamma\gamma -> 0 amplitude is obtained. Further a…

High Energy Physics - Phenomenology · Physics 2009-11-10 T. Binoth

We present a semi-recursive method for calculating the rational parts of one-loop amplitudes when recursion produces double poles. We illustrate this with the graviton scattering amplitude M^{1-loop}(1-, 2+, 3+, 4+, 5+).

High Energy Physics - Theory · Physics 2010-12-13 David C. Dunbar , James H. Ettle , Warren B. Perkins

We explore the combination of deterministic and Monte Carlo methods to facilitate efficient automatic numerical computation of multidimensional integrals with singular integrands. Two adaptive algorithms are presented that employ recursion…

Computational Physics · Physics 2009-11-07 N. Kauer

With the advent of generalized unitarity and parametric integration techniques, the construction of a generic Next-to-Leading Order Monte Carlo becomes feasible. Such a generator will entail the treatment of QCD color in the amplitudes. We…

High Energy Physics - Phenomenology · Physics 2014-11-20 Walter Giele , Zoltan Kunszt , Jan Winter

We present a method for the computation of hepta-cuts of two loop scattering amplitudes. Four dimensional unitarity cuts are used to factorise the integrand onto the product of six tree-level amplitudes evaluated at complex momentum values.…

High Energy Physics - Phenomenology · Physics 2012-04-18 Simon Badger , Hjalte Frellesvig , Yang Zhang

We employ the so-called companion matrix method from computational algebraic geometry, tailored for zero-dimensional ideals, to study the scattering equations. The method renders the CHY-integrand of scattering amplitudes computable using…

High Energy Physics - Theory · Physics 2015-12-22 Rijun Huang , Junjie Rao , Bo Feng , Yang-Hui He

A brief overview of some recently active topics in perturbative QCD, including: string-inspired recursion techniques at tree level; recursion approaches and automation of standard techniques for 1-loop calculations; the status of NNLO jet…

High Energy Physics - Phenomenology · Physics 2017-08-23 Gavin P. Salam

In this talk, the program package GOSAM is presented, which can be used for the automated calculation of one-loop amplitudes for multi-particle processes. The integrands are generated in terms of Feynman diagrams and can be reduced by…

High Energy Physics - Phenomenology · Physics 2012-01-19 G. Cullen , N. Greiner , G. Heinrich , G. Luisoni , P. Mastrolia , G. Ossola , T. Reiter , F. Tramontano

We describe the unitarity approach for the numerical computation of two-loop integral coefficients of scattering amplitudes. It is well known that the leading propagator singularities of an amplitude's integrand are related to products of…

High Energy Physics - Phenomenology · Physics 2017-06-07 S. Abreu , F. Febres Cordero , H. Ita , M. Jaquier , B. Page

We combine the observable-based formalism (KMOC), the analytic properties of the scattering amplitude, generalised unitarity and the heavy-mass expansion with a newly introduced IBP reduction for Fourier integrals, to provide an efficient…

High Energy Physics - Theory · Physics 2024-12-17 Giacomo Brunello , Stefano De Angelis

Recently, the spinor helicity formalism and on-shell superspace were developed for six-dimensional gauge theories with (1,1) supersymmetry. We combine these two techniques with (generalised) unitarity, which is a powerful technique to…

High Energy Physics - Theory · Physics 2011-03-02 Andreas Brandhuber , Dimitrios Korres , Daniel Koschade , Gabriele Travaglini

We review the recently developed bootstrap method for the computation of high-multiplicity QCD amplitudes at one loop. We illustrate the general algorithm step by step with a six-point example. The method combines (generalized) unitarity…

High Energy Physics - Phenomenology · Physics 2008-11-26 Carola F. Berger

We propose an effectively nonperturbative approach to calculating scattering amplitudes in the perturbative regime. We do this in a discretized momentum space by using the QSE method to calculate all the contributions (to all orders in…

High Energy Physics - Phenomenology · Physics 2018-07-20 Neil Christensen , Joshua Henderson , Santiago Pinto , Cory Russ

We review the current status of high-multiplicity double-virtual QCD corrections to processes relevant for LHC phenomenology. In particular, we discuss the recent full-color calculation of the five-parton process, whose two-loop amplitudes…

High Energy Physics - Phenomenology · Physics 2024-06-27 Giuseppe De Laurentis

We present a novel approximation method that can predict the number of solitons asymptotically appearing under arbitrary rapidly decreasing initial wave packets. The number of solitons can be estimated without integration of the original…

Exactly Solvable and Integrable Systems · Physics 2017-06-07 Hironobu Fujishima , Tetsu Yajima

Various implementations of the Unitarity method have been developed to compute one-loop amplitudes in gauge theories. In this paper we present an implementation which uses canonical forms to generate the rational coefficients of the basis…

High Energy Physics - Phenomenology · Physics 2009-11-24 David C. Dunbar , Warren B. Perkins , Edmund Warrick

Splitting amplitudes govern the behavior of scattering amplitudes at the momenta of external legs become collinear. In this talk we outline the calculation of two-loop splitting amplitudes via the unitarity sewing method. This method…

High Energy Physics - Phenomenology · Physics 2010-11-15 Z. Bern , L. J. Dixon , D. A. Kosower

We recompute the functions describing the collinear factorization of one-loop amplitudes using the unitarity-based method. We present the results in a form suitable for use as an ingredient in two-loop calculations. We also present a…

High Energy Physics - Phenomenology · Physics 2008-11-26 David A. Kosower , Peter Uwer

In these proceedings we report our progress in the development of the publicly available C++ library NJet for accurate calculations of high-multiplicity one-loop amplitudes. As a phenomenological application we present the first complete…

High Energy Physics - Phenomenology · Physics 2015-06-18 Simon Badger , Benedikt Biedermann , Peter Uwer , Valery Yundin
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